This happens because openbios accesses unassigned memory during the SBus
scan:
Probing SBus slot 0 offset 0
invalid accepts: (null) addr 20000000 size: 1
Probing SBus slot 1 offset 0
invalid accepts: (null) addr 30000000 size: 1
Probing SBus slot 2 offset 0
invalid accepts: (null) addr 40000000 size: 1
Probing SBus slot 3 offset 0
Probing SBus slot 4 offset 0
invalid accepts: (null) addr 60000000 size: 1
Probing SBus slot 5 offset 0
Thread 4 "qemu-system-spa" hit Breakpoint 1, memory_region_access_valid
(mr=0x555555df20c0 <io_mem_unassigned>,
addr=536870912, size=1, is_write=<optimized out>, attrs=...)
at .../softmmu/memory.c:1358
1358 return false;
(gdb) list
1355 if (mr->ops->valid.accepts
1356 && !mr->ops->valid.accepts(mr->opaque, addr, size, is_write,
attrs)) {
1357 fprintf(stderr, "invalid accepts: %s addr %"PRIx64 " size:
%d\n", mr->name, addr, size);
1358 return false;
1359 }
(gdb) p mr->ops->valid.accepts
$1 = (_Bool (*)(void *, hwaddr, unsigned int, _Bool, MemTxAttrs))
0x555555736f10 <unassigned_mem_accepts>
(gdb) list unassigned_mem_accepts
1271
1272 static bool unassigned_mem_accepts(void *opaque, hwaddr addr,
1273 unsigned size, bool is_write,
1274 MemTxAttrs attrs)
1275 {
1276 return false;
1277 }
--
You received this bug notification because you are a member of qemu-
devel-ml, which is subscribed to QEMU.
https://bugs.launchpad.net/bugs/1892540
Title:
qemu can no longer boot NetBSD/sparc
Status in QEMU:
New
Bug description:
Booting NetBSD/sparc in qemu no longer works. It broke between qemu
version 5.0.0 and 5.1.0, and a bisection identified the following as
the offending commit:
[5d971f9e672507210e77d020d89e0e89165c8fc9] memory: Revert "memory:
accept mismatching sizes in memory_region_access_valid"
It's still broken as of 7fd51e68c34fcefdb4d6fd646ed3346f780f89f4.
To reproduce, run
wget http://ftp.netbsd.org/pub/NetBSD/NetBSD-9.0/images/NetBSD-9.0-sparc.iso
qemu-system-sparc -nographic -cdrom NetBSD-9.0-sparc.iso -boot d
The expected behavior is that the guest boots to the prompt
Installation medium to load the additional utilities from:
The observed behavior is a panic:
[ 1.0000050] system[0]: trap 0x29: pc=0xf0046b14 sfsr=0xb6 sfva=0x54000000
[ 1.0000050] cpu0: data fault: pc=0xf0046b14 addr=0x54000000
sfsr=0xb6<PERR=0x0,LVL=0x0,AT=0x5,FT=0x5,FAV,OW>
[ 1.0000050] panic: kernel fault
[ 1.0000050] halted
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